Many batteries comprise one or more cells that each include an anode and a cathode separated by one or more layers of electrolyte and/or other components. For example, a lithium-ion battery may include a cathode, a layer of lithium cobalt oxide placed over the cathode, a separator layer placed over the cathode, a layer of lithium placed over the separator, and an anode placed over the lithium layer. Often, electrolyte layers (such as lithium cobalt oxide) may be sensitive to environmental exposure. Packaging may be placed around an assembly of one or more cells in order to protect the assembly against moisture, oxygen, and/or other environmental components that may ruin the assembly.
Such packaging may include placing a cell between a lower pouch sheet and an upper pouch sheet and then sealing and folding the edges of the pouch sheets to reduce space consumed. However, the folded portions still add to the horizontal dimensions of the packaged cell. Also, the seals may leave empty space between the cell and the pouch, further increasing the horizontal dimensions of the packaged cell. Given that a particular battery often may be required to fit within particular size limitations of a device into which the battery is incorporated, any increase to portions of the dimensions of the battery not occupied by energy storing portions of the battery reduces battery density (the amount of energy that a battery can store within particular dimensions). Further, this sort of packaging generally requires the battery to be rectilinear, meaning that the battery cannot fit into a non-square region of a device (such as if a battery compartment has a rounded bottom).